The holiday decorations being unveiled Wednesday by first lady Michelle Obama include 3-D printed ornaments designed by students, tinkerers, engineers and artists from around the country.

There's also an interactive installation in the East Garden Room that allows people to visualize themselves in a snowscape projected on the wall.

Also new this year are two Christmas trees created from dress-form mannequins and showcased in the Vermeil Room. Designer Alexis Bittar created ornaments and jewelry for the dress forms, including necklaces made of Lucite ivory pinecones and vintage broaches.

Overall, 26 Christmas trees are on display and there's more than a mile of knotted ribbon in the animated replicas of first dogs Bo and Sunny.

Other figures bring to life the over-the-top scale of the gingerbread house in the State Dining Room. The house contains 250 pounds of pastillage, 40 pounds of marzipan, 25 pounds of gum paste, 80 pounds of gingerbread dough and 25 pounds of sugar work.

This year's theme for the White House decorations is "a children's winter wonderland." In the State Dining Room, ornaments that resemble Scrabble tiles spell out "Winter Wonderland" on the mantle.

About 65,000 people are expected to visit the White House during the holidays.